Approach to Increased Pedestrian Safety in Lower Leg to Bumper Collisions

Euromotor Course - New Advances in Body Engineering, 28.11.2002 ika, Aachen

Dipl.-Ing. Harald Bachem,
cand.-Ing Mathias Bischoff,
cand.-Ing. Manuel Löwer, Institut für Kraftfahrwesen Aachen (ika)

Abstract:

The claims for safety of vehicles rose steadily. Reasons therefore can be found in the more and more extensive legal regulations as well as in the proceeding material development, innovative design methods and acceptance of this development from customer's side. After having significantly increased the passenger protection by crash-optimised vehicle structures and improved restraint systems, strengthened endeavours in the area of pedestrian protection can be recognised since the beginning of the eighties. Pedestrian protection plays a more and more important role at the improvement of the passive safety of modern cars.
In this lecture first of all the historical development of the legislative concerning pedestrian safety is explained. Results of experiments are shown, in which the quasi statical and dynamical structural behaviour of polymer foams, that are suitable for the usage in bumper systems, is investigated. In an extensive testing series especially the influences of strain rate and temperature effects are analyzed. Afterwards a parameter study under usage of the Finite Element Method is presented for the construction of pedestrian friendly bumper system. For this purpose numerical simulations with a MADYMO model for the lower leg are fulfilled, which is validated for the testing procedure according to EEVC WG-17 (European Enhanced Vehicle Committee, Working Group 17). An extensive simulation plan is built up, in which the most important construction parameters are varied in a realistic range. The results of the study can be used as an input for a construction guideline for the pedestrian friendly optimization of future bumper systems.